The design, manufacture, and assembly of mattresses, mattress foundations, upholstered furniture articles and other articles filled with resilient cushioning materials has varied little in the history of these products. The primary areas of innovation have occurred with the introduction of new filling materials.
According to the International Sleep Products Association (ISPA), the domestic US mattress industry shipped mattresses and foundation units in 2010 totaling 34 million units or roughly 17 million sets of bedding with a retail value in excess of $11 billion.
Numerous filling materials are used to construct mattresses, mattress foundations, upholstered furniture articles and other articles filled with resilient cushioning materials. These can be made from, for example, foam, fiber or other similar resilient material.
Manufacturers of flexible polyurethane foam, textile fibers, and other resilient filling materials employ a wide variety of technical measurements to communicate the performance attributes engineered into particular foams. Such technical measurements include indentation force deflection (IFD), indentation load deflection (ILD), tensile strength, tear strength, density pounds per cubic foot (PCF), flex fatigue, denier, cut length, and basis weight.
Materials may be further differentiated by their composition. In the case of flexible polyurethane foams, for instance, there are visco-elastic foams, latex foams, gel-infused foams, memory foams, conventional foams, filled conventional foams, high resiliency (HR) foams, modified HR foams, combustion modified foams, melamine modified foams—all of which can be made at differing densities and hardnesses making the possible total number of combinations potentially limitless.
It is well known that flexible foam materials have demonstrably different levels of flame retardance. For instance, latex foam is highly flammable and therefore, presents a much more difficult fuel load to protect from open flame ignition sources than that of the fuel load of a standard polyurethane foam. The need for protection based on foam type impacts the manufacturers' selection of fire barrier materials.
During the last several years, U.S. mattress manufacturers have manufactured “one-sided” mattresses.
Using marketing that intimates that this is preferable to the consumer as they no longer have to “flip” their mattress, the fact is that the manufacture of a “one-sided”, “non-flippable” mattress is both a sales growth and cost saving effort by manufacturers. It is a sales growth effort in that a two-sided mattress could reasonably be expected to have twice the useful life expectancy of the current one-sided units, so shortening the life span results in increase purchase frequency by consumers—a potential sales doubler. The cost cutting aspect is a result of removing the costly comfort delivering fillings on one-side of the mattress. Not surprisingly, retail price points for mattresses did not decline commensurately to reflect the life shortening and cost reductions when this product change occurred.
Much of the growth of one-sided mattresses began with the AB 603 mattress flammability standard in California and later reached near universal design adoption that coincided with the implementation of the Federal Mattress Flammability Standard 16 CFR 1633 in 2007. Many mattress manufacturers determined that typical, tape-edged and two-sided mattresses had a crown or convex surface profile on the panel planar surface of the mattress that when placed on a flat foundation structure created a crevice between mattress and foundation that present testing challenges. Removing one convex side from the mattress design eliminated the crevice and facilitated testing compliance.
The design evolution of mattresses away from two-sided constructions and toward one-sided constructions has several, potentially adverse implications for consumers that have not been effectively addressed by manufacturers.
The resilient cushioning materials used by mattress manufacturers to create the sleeping surface of the mattress and to afford the user a level of comfort while sleeping are prone to physical breakdown during use. This is referred to as “taking a set” and the mattress industry itself describes the presence of these body impressions as “normal”. Over time, these body impressions do degrade the sleep experience and the benefits sought to be derived from the sleep experience. In a two-sided mattress, users were instructed to flip and rotate the mattress every several months to balance the occurrence of the impressions—in a traditionally designed one-sided, no-flippable mattress, this option to promote longevity is reduced. In fact, current marketing of mattresses touts the lack of “maintenance” required for one-sided mattresses.
Second, the traditional approach to mattress design has been to construct the product in such a manner as to preclude the end-user from being able to access interior components of the mattress. As the cushioning materials physically breakdown, the end-user is left with no alternative but to replace the entire mattress assembly in order to rectify the body impressions condition. Given that conventional end-of-life-cycle disposal of mattresses has been to place them in landfills, the increasing pace at which the one-sided mattress design can be expected to result in disposal and replacement, the potential waste-stream impact of the one-sided mattress in potentially substantial.
While the retail mattress world has been flocking to the one-sided mattress design, one arena where two-sided mattresses still find wide acceptance is in college dormitory environments. Since institutional purchasers, such as college and university residence life operations, view residence hall mattresses as an asset whose value is enhanced with longer service life, the ability to flip mattresses with a two-sided traditional mattress design has remained desirable.
Some two-sided institutional mattress designs promote the benefit of a dual firmness design, wherein the filling materials selected for one of the two sides is chosen to be “soft” and the other side's materials are chosen to be “firm”, thereby permitting the end-user to custom select their preferred sleep surface.
The invention captures the benefits of both the one-sided design and the dual-firmness design approach of certain two-sided mattresses simultaneously, and does so in a manner that can afford environmentally conscious end-users with the ability to reduce the waste stream impact of disposal of mattresses when filling materials degrade after their useful life expectancy. Since the upper comfort layer assembly is accessible to the end-user, the foam or filling materials may be replaced when, through the normal course of use or in the event of damage, the end-user wishes. The ability to replace only the upper comfort layer foam or filling materials and the fire barrier that encases them, while preserving for use the remaining mattress components results in a lessened disposal impact. Additionally, the detachable cover assembly itself may be replaced if worn or soiled, again permitting the preservation of the remaining, still serviceable mattress components and lessening the disposal impact.
The invention further delivers the benefit of material design flexibility as it relates to fire barrier selection, especially in the case of knitted, tubular fire barriers, to meet requirements of full-scale fire testing, such as 16 CFR 1633. Heretofore, conventional mattress design approaches have elected to substantially encase the entire mattress structure in fire barrier material capable of addressing the worst-case flammability profile of components or filling materials selected for construction of the mattress. For instance, if a mattress design used a combination of highly flammable materials, such as latex foam, in conjunction with materials that were less flammable, such as standard polyurethane foam or foams that are moderately combustion modified, then the barrier would likely have to be chosen from a more robust, therefore heavier and more expensive fire barrier design that could address the flammability profile of the worst-case component—in this case latex foam. The invention, through its use of a plurality of fire barriers, provides the potential to tailor the fire barrier selection to each specific region of the mattress and its associated propensity to ignite when exposed to an open-flame ignition source, and therefore achieve material efficiencies not afforded by pre-existing design approaches. The use of a plurality of independent fire barrier systems allows the flexibility of design that enables the targeted selection fire barriers to address the specific and potentially disparate flammability characteristics for various elements of the present invention